This application relates to a device for fixing an airbag, which is fastened to a holding frame, in a housing of a front passenger airbag module.
Various solutions are known for fixing an airbag which is fastened to a holding frame in a housing of an airbag module. For example, an airbag module is known from DE 198 50 463 A1 (incorporated by reference herein) in which an airbag is connected to a holding frame which has locking elements to fix the holding frame, and therefore the airbag, in the housing. This airbag module has the disadvantage that welding of the folded airbag into a flexible protective cover enclosing the airbag packet is made more difficult because of the locking elements. The gastight enclosure makes it possible to minimize the dimensions of the airbag packet by generating a low pressure in the flexible protective cover. A further disadvantage is that the housing must have a double-walled configuration in the locking region.
In the airbag module known from the application GB 2 323 572 A the holding frame of the airbag has locking elements in the form of latching hooks that engage in openings of the airbag housing. In this arrangement, too, there is the disadvantage that welding-in of the folded airbag is made more difficult because of the locking elements.
Known from U.S. Pat. No. 5,556,124 (incorporated by reference herein) is an airbag module in which the holding frame of the airbag is held between projections inside the airbag housing. The housing consists of a main part with a U-shaped cross-section and two end parts. The holding frame must be inserted into the housing prior to installation of the end parts since the side walls of the main part must be pressed away from one another by the holding frame as it is inserted into the housing from above in order to position the holding frame between the projections. If the airbag packet is surrounded by a protective cover and the holding frame is also contained in the protective cover, the protective cover can be damaged when pushing away the housing walls. Furthermore, this arrangement has the disadvantage that extensive assembly work is required because of the three-part housing.
Finally, a modular assembly for an airbag arrangement is known from the utility model DE 20 2005 009 002 U1 (incorporated by reference herein), in which the holding frame is retained by fastening mechanisms that extend over the holding frame. In this case, the holding frame is first positioned in the airbag housing. The fastening mechanisms are then inserted and screwed or riveted to the housing. It is further known from this document to fix the holding frame by means of a clamp. In this case the annular clamp, which is split at one point, is spread after fixing of the airbag packet and fitted from outside over the holding frame and a housing base plate. The clamp is then pulled together in the region of the split by a screw and nut. These arrangements have the disadvantage that screwing or riveting operations are required for fixing.
In one embodiment in this document a clamp is provided that connects to one another a housing part which extends over the holding frame and a support plate on which the holding frame is located. This clamp is either under elastic pretension or is plastically deformable. With this embodiment, the protective film over the airbag can be damaged when installing the clamp.